Head stabilizing system

ABSTRACT

A head stabilizing system is provided. The head stabilizing system is intended to minimize loads on the head and the neck, some of which may be injurious or even fatal, by generating a reaction force that substantially opposes a force acting on the head and generated by rapid deceleration of a vehicle or a crash impact. The head stabilizing system includes a helmet, a connection structure, and at least one resisting member. The resisting member generates a reaction force that opposes the crash impact force, yielding a reduced net force on the head. This reaction force can be generated as a function of position, velocity or acceleration. The resisting member may include a tether, a dashpot, or a dashpot containing a controllable rheological fluid. The viscosity of the controllable rheological fluid can be automatically adjusted in response to changes in status of a vehicle or it&#39;s occupant.

This application claims priority under 35 U.S.C. § 119 based on U.S.Provisional Application No. 60/312,754, filed Aug. 17, 2001, and U.S.Provisional Application No. 60/315,359, filed Aug. 29, 2001, thecomplete disclosures of which are incorporated herein by reference.

DESCRIPTION OF THE INVENTION

1. Field of the Invention

The present invention relates to a head stabilizing system forminimizing loads on the head and the neck, some of which may beinjurious or even fatal, by generating a reaction force thatsubstantially opposes a force acting on the head and generated by rapiddeceleration of a vehicle or a crash impact.

2. Background of the Invention

Activities that involve high speed, such as racing cars or boats andflying aircraft, involve a large risk of a high speed crash. Suchcrashes involve rapid deceleration of the vehicle and the portion of itsoccupant connected, via seatbelt or harness, to the vehicle. However,the head and the neck of the occupant are generally not connected to theseat, and thus the head of the occupant accelerates rapidly with respectto the body, exerting a large force on the base of the skull, the neckmuscles, ligaments, and the spinal cord of the occupant, and creating alarge risk for severe head and neck injuries. Injuries caused by violenthead movement were the most common cause of death among race car driversduring the last decade. When the head accelerates rapidly with respectto the body, large loads on the neck will occur, commonly resulting inbasilar skull fracture, a condition in which the base of the skullcracks from stress, often causing trauma to arteries and the spinalcord.

Several head and neck protection devices have been developed to protectindividuals from injury during rapid deceleration. For example, onedevice attaches a helmet to a yoke to be fitted around a wearer'sshoulders. By attaching the helmet to the yoke around a user'sshoulders, force is transferred away from the neck of the wearer throughthe device to the shoulder harness of a vehicle. Another device,disclosed in U.S. Pat. No. 5,371,905, limits motion of the head due toactuation of a valve achieved by attaining a minimum velocity of thehead. Other devices include helmets attached to a wearer's yoke, to theseat or other fixed portion of the vehicle, or a network of webbing wornby the driver. Many of these devices restrict movement of the wearerduring normal use, making the devices cumbersome and even dangerous towear, due, for example, to their potential for limiting drivervisibility, interference with control of the vehicle, or inhibiting thewearer's ability to exit the vehicle in the event of fire.

SUMMARY OF THE INVENTION

In accordance with the invention, a system for stabilizing the headduring deceleration is provided, the system generates a reaction forcethat substantially opposes the force generated by the deceleration,yielding a reduced net force on the head.

According to one aspect of the present invention, a head stabilizingsystem for limiting the load acting on a wearer's head and generated bydisplacement, velocity, or acceleration of the wearer's head withrespect to the wearer's body is provided. The system comprises a helmet,a connection structure, and at least one resisting member positionedbetween and connected to the helmet and the connection structure,wherein the at least one resisting member generates a reaction forcethat substantially opposes a crash impact force to yield a reduced netforce on the head.

According to another aspect of the present invention, a head stabilizingsystem for limiting the load acting on a wearer's head and generated bydisplacement, velocity, or acceleration of the wearer's head withrespect to the wearer's body is provided. The system comprises aresisting member having first and second ends, a helmet mount connectorfor connecting the resisting member to a helmet, the helmet mount beingattached to the first end of the resisting member, and a movable harnessconnector for connecting a safety harness of a vehicle to the resistingmember, the harness connector being attached to the second end of theresisting member.

According to a further aspect of the present invention, a headstabilizing system for limiting the load acting on a wearer's head andgenerated by displacement, velocity, or acceleration of the wearer'shead with respect to the wearer's body comprises a helmet, and means forgenerating a reaction force that substantially opposes a crash impactforce to yield a reduced net force on the head.

According to yet another aspect of the present invention, anautomatically adjustable head stabilizing system for limiting the loadacting on a wearer's head and generated by displacement, velocity, oracceleration of the wearer's head with respect to the wearer's body isprovided. The system comprises a helmet, a connection structure, meansfor continuously monitoring a status of a vehicle and/or driver, and atleast one dashpot containing a controllable rheological fluid, the atleast one dashpot positioned between and connected to the helmet and theconnection structure, wherein the viscosity of the rheological fluid inthe dashpot automatically changes in response to or in anticipation of achange in a load being applied to the helmet and head of the wearer.

According to another aspect of the present invention, an automaticallyadjustable head stabilizing system for limiting the load acting on awearer's head and generated by displacement, velocity, or accelerationof the wearer's head with respect to the wearer's body comprises abladder positionable around a wearer's neck and containing acontrollable rheological, wherein the viscosity of the rheological fluidin the bladder automatically changes based on changes in a load beingapplied to the head of the wearer.

According to a further aspect of the present invention, a method ofautomatically limiting the load acting on a wearer's head and generatedby displacement, velocity, or acceleration of the wearer's head withrespect to the wearer's body is provided. The method comprises providingan occupant of a moving vehicle with a system comprising a helmet, aconnection structure, means for continuously monitoring a status of avehicle and/or driver, and at least one dashpot containing acontrollable rheological fluid, the at least one dashpot positionedbetween and connected to the helmet and the connection structure,wherein the viscosity of the rheological fluid in the dashpotautomatically changes in response to or in anticipation of a change in aload being applied to the helmet and head of the wearer, continuouslymonitoring the status of at least one of the vehicle and the occupant,and automatically changing the viscosity of the rheological fluid in thedashpot in response to changes in the status.

According to yet another aspect of the present invention, a method ofautomatically limiting the load acting on a wearer's head and generatedby displacement, velocity, or acceleration of the wearer's head withrespect to the wearer's body includes providing an occupant of a movingvehicle with a system comprising a bladder positionable around awearer's neck and containing a controllable rheological, wherein theviscosity of the rheological fluid in the bladder automatically changesbased on changes in a load being applied to the head of the wearer,continuously monitoring the status of at least one of the vehicle andthe occupant, and automatically changing the viscosity of therheological fluid in the dashpot in response to changes in the status.

According to yet another aspect of the present invention, a headstabilizing system for limiting the load acting on a wearer's head andgenerated by displacement, velocity, or acceleration of the wearer'shead with respect to the wearer's body comprises a helmet having anupper portion and a lower portion connected via a hinge, and at leastone resisting member having a first end connected to the upper portionof the helmet and having a second end connected to the lower portion ofthe helmet, wherein the at least one resisting member generates areaction force that substantially opposes a crash impact force to yielda reduced net force on the head.

Additional advantages of the invention will be set forth in part in thedescription that follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention will be realized and attained by meansof the elements and combinations particularly pointed out in theappended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of theinvention and together with the description, serve to explain theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view of a head stabilizing system according to oneaspect of the present invention;

FIG. 1B is a side view of an alternative embodiment of a headstabilizing device according to one aspect of the present invention;

FIG. 1C is a side view of an alternative embodiment of a headstabilizing device according to one aspect of the present invention;

FIG. 2A is a side view of an alternative embodiment of a headstabilizing system according to another aspect of the present invention;

FIG. 2B is a side view of an alternative embodiment of a headstabilizing system according to another aspect of the present invention;

FIG. 3 is a side view of an alternative embodiment of a head stabilizingsystem according to another aspect of the present invention;

FIG. 4 is an isometric view of a damping mechanism used in the presentinvention;

FIG. 5A is a side view of an alternative embodiment of a headstabilizing system according to another aspect of the present invention;

FIG. 5B is a side view of an alternative embodiment of a headstabilizing system according to another aspect of the present invention;

FIG. 5C is a top view of a damping mechanism and connectors according toone aspect of the invention;

FIG. 5D is a top view of a mounting device for a helmet according to oneaspect of the present invention;

FIG. 5E is a side view of the mounting device of FIG. 5D;

FIG. 5F is a front view of the mounting device of FIG. 5D;

FIG. 5G is a side view of an alternative embodiment of a headstabilizing system according to another aspect of the present invention;

FIG. 5H is a back view of the head stabilizing system of FIG. 5G;

FIG. 6 is a force diagram showing the forces used to calculate a dampingcoefficient according to one aspect of the present invention;

FIGS. 7A and 7B are alternative force diagrams, including a spring,showing the forces used to calculate a damping coefficient according tothe present invention;

FIG. 8 is a side view of an automatic head stabilizing system accordingto one aspect of the present invention; and

FIG. 9 is a side view of another embodiment of an automatic headstabilizing system according to another aspect of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiment of theinvention, an example of which is illustrated in the accompanyingdrawings.

Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

The present invention comprises a system for protecting the head andneck of the user during rapid deceleration. The system is intended toprevent any substantial increase or decrease in the distance between thehead and the body when the head and body are moving at high velocity,for example, in a race car. The system includes at least one resistingmember that generates a reaction force that substantially opposes acrash impact force, yielding a reduced net force on the head during acrash event.

When a wearer of a helmet or other protective device is in a rapidlymoving vehicle, unless there is a crash, the velocity and accelerationof the wearer's head with respect to his body is very low. Specifically,the body and head are moving at the same speed within the vehicle, andany movement of the head with respect to the body is relatively slow, orat low velocity. However, in a crash situation, the wearer's body, whichis strapped to the car, rapidly decelerates as the vehicle deceleratesupon impact. The wearer's head, however, is not connected to the vehicleand continues to move at the same high velocity. Therefore, the head'svelocity, with respect to the body, accelerates from approximately zeroto an extremely high velocity almost immediately. For example, a racecar crash can typically generate a force of approximately 50 times thepull of gravity in the driver's compartment, and generate a forceapproximately twice that, or approximately 100 times the pull ofgravity, on the head itself. The entire crash event occurs in less thanone tenth of a second, and peak head and neck loads occur in less thanthirty milliseconds. This rapid acceleration of the head with respect tothe body generates large loads on the head that may compress or stretchthe neck, causing the distance between the head and the body tosubstantially change and resulting in severe injury or death. Othercrash events generate different load patterns, but all result in rapidhead acceleration relative to the body within a very short period oftime. Thus, there are different requirements for a protective systemdepending upon the situation.

During normal use, i.e., in a non-crash situation where head velocity islow, it is important that the wearer is able to move his head freely—anymovement of the head with respect to the body will be at a low velocity.This is particularly important to prevent interference with the wearer'svisibility and control of the vehicle due to a limited or restrictedrange of motion. In a crash situation, because the head acceleratesalmost instantaneously to an extremely high value with respect to thewearer's body (which is strapped to the vehicle and decelerates withimpact of the vehicle), it is important that the protective system becapable of offsetting the loads generated by the head moving at a highvelocity with respect to the body in order to minimize injury.

The present invention allows low velocity motion of the head withrespect to the body, reduces high velocity motion of the head withrespect to the body, and generates a reaction force that offsets theloads generated by the rapid acceleration of the head with respect tothe body. This is accomplished through the use of at least one resistingmember. As used herein, a “resisting member” is a pivotable link betweena helmet or other protective device and a connection surface. The linkis capable of generating a reaction force that opposes the crash impactforce, yielding a reduced net force on the head. This reaction force canbe generated as a function of position, velocity or acceleration. Thelink is preferably sufficiently rigid, or is capable of becomingsufficiently rigid upon the absorption of kinetic energy, tosubstantially prevent relative movement between the helmet and theconnection surface during deceleration (i.e., prevent any substantialincrease or decrease in the distance between the head and body during acrash).

The resisting member may be, for example, a tether, defined herein as asubstantially rigid link of a fixed length, such as a chain, a steel rodor cable, or nylon webbing. A tether generates a reaction force based onposition, even while a crash is not occurring. Tethers are notespecially preferred because their reaction is a function of positionand, therefore, must necessarily restrain the head, even during normal,non-impact conditions, potentially severely limiting visibility of adriver due to the fixed length of the tether. In a more preferredembodiment, the resisting member may be a damping mechanism, forexample, a damper, a dashpot, or a shock absorber. A dashpot generates areaction force based on velocity. A dashpot's reaction force only occursat a high velocity, allowing head motion at low velocities. Many of theembodiments described herein use a dashpot, although other suitabledevices capable of generating a desired reaction force may besubstituted.

At rest, the dashpot is a passive device and has substantially no forceoutput. In motion, the damping force of the dashpot is, in general,approximately linearly proportional to the velocity of the head relativeto the body and will oppose motion of the head with respect to the body.

To minimize injury to the head or neck of the wearer, it is desirable tominimize the load on the head and the neck such that it is no greaterthan approximately 3300 Newtons. When the body, strapped to the vehicle,stops moving upon impact, the head keeps moving. This causes both linearand angular acceleration of the head with respect to the body, resultingin a force acting on the upper neck. As discussed above, a crashgenerating a particular deceleration in the driver's compartment of thevehicle will cause approximately twice that deceleration to act on theupper neck. Both the linear and angular forces derive from Newton'ssecond law of motion, which states that this force is defined as masstimes acceleration, where the mass is that of the head and theacceleration is comprised of both linear and angular components. Thelinear component of the acceleration is the deceleration of the head ofthe occupant of the driver's compartment. The angular component of theacceleration is defined as ω²r, where omega (ω) is the angular velocityof the head about the point of relative motion, the bottom of the neckrepresented in FIG. 1A as the C7/T1 junction, and r is the radius,defined here as the distance from the bottom of the neck to the centerof gravity of the head.

In a typical impact, loads on the head go from zero to peak to zero inabout 0.05 seconds. Since the dashpot's damping coefficient is in unitsof force/distance/time, rapid motion requires more force. Thus, it iseasy for the wearer to move the head slowly with respect to the body,i.e., under non-crash conditions, and extremely difficult to move thehead quickly with respect to the body. In a crash, the force requiredfor the head to accelerate from zero to peak velocity almostinstantaneously is so high that the dashpots become virtually rigidthereby preventing any substantial increase or decrease in distancebetween the head and the body and substantially offsetting the load onthe head and the neck.

As embodied herein and shown in FIGS. 1A-2B, 5A and 5B, a headstabilizing system 100 for protecting the head and neck of a user duringrapid deceleration is provided. The system 100 includes a helmet, aconnection structure, and at least one resisting member.

According to one aspect of the present invention, a helmet 110 isprovided. The helmet 110 may be any standard helmet used by drivers orpilots for head protection. Preferably, the helmet 110 includes an outershell and an inner shell. The outer shell preferably includes a rigidmaterial such as hard plastic or a composite material. The inner shellpreferably includes some sort of padding for additional protection ofthe head.

Helmet 110 also includes at least one mounting device for connecting thehelmet 110 to at least one resisting member. As shown in FIGS. 1A and5D-5F, the mounting device may comprise a bracket 115. The number andposition of the mounting devices 115 is dependent upon and generallycorresponds to the number and position of resisting members used, aswill be described further below. It is envisioned that conventionalhelmets may be adapted for use with the system of the present inventionby installing the appropriate mounting device(s) on the helmet.

According to another aspect of the present invention, a connectionstructure is provided. As embodied herein and shown in FIGS. 1A-1C, theconnection structure may be a chest/shoulder plate 120. Chest/shoulderplate 120 includes a first shoulder portion 122 a and a second shoulderportion 122 b (not shown), which is substantially a mirror image offirst shoulder portion 122 a. Shoulder portions 122 a, 122 b may be madefrom any suitable material which can be shaped to form shoulder portions122 a, 122 b, for example, a hard plastic or composite material.Shoulder portions 122 a, 122 b are configured to fit over the shoulders,adjacent the neck, of a user. Preferably, the shoulder portions 122 a,122 b are curved to fit over the shoulders and may extend over the chestand back. The shoulder portions 122 a, 122 b may or may not be connectedto one another. Shoulder portions 122 a, 122 b may or may not beconnected to a seat belt or harness. Shoulder portions 122 a, 122 b mayfurther include a padded layer for added comfort. Shoulder portions 122a, 122 b may also include mounting devices similar to those describedfor use with helmet 110.

Alternatively, shoulder portions 122 a, 122 b may be connected to form aU-shaped yoke 122 (FIG. 2A). In such an embodiment, a collar portionintended to extend behind the neck connects the shoulder portions 122 a,122 b, and shoulder portions 122 a, 122 b extend from the collar portionand over the chest of the wearer. Examples of such a helmet and shoulderrestraint combination are disclosed in U.S. Pat. No. 4,638,510, issuedJan. 27, 1987, and U.S. Pat. No. 6,009,566, both of which areincorporated herein by reference.

In another embodiment, the helmet 110 may be attached to a connectionstructure other than a shoulder/chest plate. For example, the helmet maybe attached to the seat of the vehicle, the roll cage of the vehicle,the frame of the vehicle, the shoulder harness 150 of the vehicle (FIGS.5A and 5B), or a component worn by the driver such as a network offlexible webbing. Alternatively, a connection structure may not beprovided, as described later with respect to FIG. 3.

As embodied herein and shown in FIGS. 1A-1C, 2A-2B, and 5A-5B, system100 includes at least one resisting member. As shown in FIGS. 1A-1B,2A-2B, and 5A, the resisting member may be a damping mechanism 130, suchas a damper, dashpot or shock absorber, which contains a fluid, eithergas or liquid. As embodied herein and shown in FIG. 4, a dashpot 130comprises a piston 132, a low friction hollow cylinder 134, a first end136 and a second end 138. Dashpot 130 may include an orifice that isadjustable to select the damping coefficient of the dashpot, althoughthe orifice may be fixed to prevent tinkering. The piston 132 forcesfluid through the orifice at a controlled rate to dissipate kineticenergy when the piston is being moved. Presently, a bi-directionaldashpot, which works in both the pulling and the pushing direction, ispreferred. By adjusting the rate at which fluid can be forced throughthe orifice (e.g., by changing the size of the orifice) the dampingcoefficient of the dashpot 130 can be selected. The damping coefficientshould be selected to allow the dashpot to generate a reaction force tooffset the force on the head and neck created by a crash.

As discussed earlier, the force that causes injury during impact is aresult of the crash generating a particular deceleration in the vehiclethat causes a deceleration of approximately twice that to act on thehead and the upper neck. The actual value of the force generated duringa crash can be estimated. Force is defined as mass times acceleration,where the mass is that of the head and the acceleration is comprised ofboth linear and angular components. The linear component of theacceleration is the deceleration of the head of the occupant of thedriver's compartment. The angular component of the acceleration isdefined as ω²r, where omega (ω) is the angular velocity of the headabout the point of relative motion, the bottom of the neck representedin FIG. 1A as the C7/T1 junction, and r is the radius, defined here asthe distance from the bottom of the neck to the center of gravity of thehead.

According to established research (Accidental Injury, Biomechanics andPrevention, Alan M. Nahum and John W. Melvin, 1993), the externalaccelerations experienced by the human head during an accident arerepresented by a ramp-shaped function of as much as 160 times gravityand are felt for a duration of less than 50 milliseconds. The maximumallowable load on the neck before major injury occurs is approximately3300 Newtons. Information such as the mass of the occupant's head andhelmet is available, and for purposes of testing only, the inventor hasassumed a total mass of approximately 15 lbs.

In order to minimize injury, the dashpot must generate a reaction forcesubstantially equal to that generated by the crash, but acting in adirection opposite to the force exerted on the head and neck by thecrash. By generating a substantially equal yet opposite force, thedashpot minimizes the net load acting on the head and neck, therebyminimizing the chance of injury. Using the above information regardingtotal mass and acceleration, the maximum allowed load on the head andneck, and the general duration of the crash event, it is possible todetermine the damping coefficient of the dashpot necessary to generatethe desired reaction force. Based upon the assumptions given above, theinventor has determined that a total damping coefficient of betweenabout 4 and 15 lb/in/sec is preferred, with a total damping coefficientof about 8 lb/in/sec being most preferred, given typical mountinggeometry. The damping coefficients of all dashpots within the system,added together, gives the “total damping coefficient.” For example, fora total damping coefficient of 8 lb/in/sec, when two dashpots are usedwithin the system, each dashpot would have a damping coefficient ofabout 4 lb/in/sec, and if 4 dashpots were used in the system, eachdashpot would have a damping coefficient of about 2 lb/in/sec.Similarly, if only a single dashpot was used in a system, the dashpotwould preferably have a damping coefficient of about 8 lb/in/sec.

It should be noted that dashpots having non-constant dampingcoefficients, or coefficients that differ in extension and incompression could be used as alternatives to the simple dashpotsdescribed herein. Also, design objectives that call for different impactloads, head and neck loads, or limitations to range of motion wouldresult in a different range of damping coefficients and possiblydifferent dashpot geometry.

As shown in FIGS. 1A-1C, first ends 136 of resisting members 130 areconnected to the helmet 110 by pivoting mechanisms such as ball joints136 a. Alternatively, as embodied herein and shown in FIG. 5C, resistingmember 130 may include a helmet mount connector 160 for connecting theresisting member 130 to the bracket 115 on the helmet 110. Any suitablestructure configured to fit with the bracket 115 may be used.Preferably, the helmet mount connector includes a quick release pin 162to enable quick connection and release from the bracket/mounting device115 on the helmet. Preferably, the helmet mount connector 160 isconfigured to connect to any helmet mounting device 115, therebyenabling more than one helmet to be used with the system. For example, asystem 100 may be connected to a portion of a vehicle, such as thesafety harness, and multiple drivers may utilize the system byconnecting the helmet mount connector 160 to a mounting device 115 ontheir helmet.

Second ends 138 of resisting members 130 are connected to shoulder/chestplate 120. Alternatively, the resisting member 130 may be connected to aportion of the vehicle, such as the safety harness 150 as shown in FIGS.5A and 5B.

As embodied herein and shown in FIG. 5C, resisting member 130 may beprovided with a rolling harness connector 155. Rolling harness connector155 includes a wide, squared U-shaped body 157 having holes 158 in legs157 a of the body. A quick release pin 159 for permitting attachment anddetachment from the harness 150 passes through holes 158. A hollowsupport tube (not shown) may be placed over pin 159 to provideadditional strength in anticipation of impact forces exerted on the pin.The safety harness 150 fits between the body 157 of connector 155 andpin 159. Pin 159 rolls on harness 150, allowing movement of the headwith respect to the body when the resisting member is connected to thehelmet 110. Alternatively, as shown. in FIGS. 5G and 5H, the rollingharness connector 155 may be a sliding harness connector 155 a. Thisharness connector 155 a does not include a round pin for rolling, butmay include a bar or other support, which slides below the safetyharness. Similar to rolling harness connector 155, sliding harnessconnector 155 a is intended to move with the driver in the event of acrash, rather than remain fixed on the safety harness 150.Alternatively, as shown in FIG. 2B, a structure 157 a maybe be placedbelow/attached to safety harness 150. Such a configuration permitsconnection of two resisting members 130 to the structure 157 a.

Using ball and socket type connections between helmet 110 and resistingmembers 130 and between resisting members 130 and shoulder/chest plate120 allows freedom of movement of helmet 110 with respect toshoulder/chest plate 120, i.e., movement of helmet 110 is not restricteddue to its connections to shoulder/chest plate 120. Piston rod length ofthe resisting member(s) 130 must be sufficient to allow for adequatemotion of the head, such as tilting and turning the head.

As shown in FIG. 1A, four resisting members 130 may be used, twoconnected to each shoulder portion 122 a, 122 b. Alternatively, as shownin FIG. 1B, a single resisting member 130 may connect between the helmet110 and shoulder/chest plate 120. As shown in FIGS. 1C and 5B, theresisting member 130 may be a tether instead of a dashpot.Alternatively, as shown in FIG. 2B, two resisting members 130 may beused, each connected to the structure 157 a. In addition, two of thestructures 157 a may be provided, one under each shoulder harness,allowing the use of four resisting members. The number of resistingmembers 130 used and the type of connection structure used may vary,dependent upon a variety of conditions.

In use, during normal conditions, the head and body of the wearer aremoving at the same velocity within the vehicle. Any movement of thewearer's head with respect to this body will normally be a smallmovement and will be relatively slow, such as turning the head to theside to look at a mirror. Since the dashpots' damping coefficient is inunits of force/distance/time, slow motion requires relatively littleforce and the wearer is therefore able to move his head and helmet withrespect to his body and connection structure. During a crash situation,the force required for the head to accelerate from zero to peak velocityalmost instantaneously is so high that the dashpots become virtuallyrigid thereby generating a reaction force that substantially opposes theload generated by acceleration of the head with respect to the body andthus preventing any substantial increase or decrease in distance betweenthe head and the neck that could cause severe injury.

According to another aspect of the invention, a head stabilizing systemfor protecting the head and neck of a user during rapid deceleration maynot include a connection structure. As embodied herein and shown in FIG.3, a system 200 includes a helmet having an upper portion and a lowerportion and at least one resisting member connecting the upper portionof the helmet to the lower portion of the helmet.

As shown in FIG. 3, a helmet 210 is provided. Helmet 210 may include anupper portion 212, a visor portion 214, and a lower portion 216. Gogglesmay replace visor portion 214. Upper helmet portion 212 is connected tolower portion 216 via hinges 218. Lower helmet portion 216 extends belowthe chin of the wearer and rests on the shoulders 250 of the wearer asshown in FIG. 3. Preferably, the helmet 210 includes an outer shell andan inner shell. The outer shell preferably includes a rigid materialsuch as hard plastic or a composite material. The inner shell preferablyincludes some sort of padding for additional protection of the head.

As embodied herein and shown in FIG. 3, resisting members are provided.The resisting members preferably comprise dashpots 230. Dashpots 230have the same structure and function as described previously withrespect to the embodiment of FIGS. 1A-1B, 2A-2B, and 5A. Dashpots 230include a first end 236 and a second end 238. First ends 236 areconnected to a lower surface of the upper helmet portion 212 and secondends are connected to an upper surface of the lower helmet portion 216.Alternatively, the hinges 218 may be replaced with rotational dashpots.

In use, during normal conditions, the head and body of the wearer aremoving at the same velocity within the vehicle. Any movement of thewearer's head with respect to this body will normally be a smallmovement and will be relatively slow, such as turning the head down tolook at a gauge. Since the dashpots' damping coefficient is in units offorce/distance/time, slow motion requires relatively little force andhelmet portions 212, 216 move freely with respect to one another,allowing the wearer to move his head with respect to his body. During acrash situation, the force required for the head to accelerate from zeroto peak velocity almost instantaneously is so high that the dashpots 230become virtually rigid. The rigidity of the dashpots 230 generates areaction force substantially opposing the load generated by the rapidacceleration of the head with respect to the body and thus prevents anysubstantial increase or decrease in the distance between the head andthe body that could cause severe injury.

The dashpots used in the above embodiments may be linear dashpots.Alternatively, in a preferred embodiment, the dashpots used are radial,or universal, dashpots. Universal dashpots are able to control motion inall directions. Use of such dashpots would be useful in situations wherethe force applied is not a linear force or is not applied from a head-oncrash. For example, in helicopter crashes, injury is due to acompressive load on the spine and displacement of the neck.Alternatively, if a car is side-swiped, the force may be horizontal. Byusing a universal dashpot, all of these types of loads can becounteracted. In an extreme situation such as providing protection for awearer in a helicopter crash or very high impact racing crash, it mayalso be desirable to include a spring in addition to the dashpot, asshown in FIGS. 7A and 7B.

A primary goal of the present invention is to prevent injury to thewearer in impact or crash situations. However, it is also desirable toprevent minor injuries, such as those caused by the forces created in“normal” situations, such as taking corners at extremely high speeds,braking, or flying in a fighter aircraft. Such “normal” activities maygenerate forces in the range of approximately 3 to 10 g, which can causestrain and/or injury to the neck. The present invention provides asystem capable of automatically adjusting to counteract the forcesapplied in any situation. Thus, if a wearer is taking a corner at highspeed, the device will become sufficiently rigid to prevent injury andreduce fatigue at that load. If a wearer is in a crash, the device willbecome sufficiently rigid to minimize injury at impact. This isaccomplished by replacing the dashpot in the previous embodiments ofFIGS. 1A-5A with an automatically adjustable damping mechanism. Thefluid-based dashpot preferably includes a controllable rheological fluidsuch as a magneto-rheological (MR) fluid or an electro-rheological (ER)fluid. Although this embodiment is discussed with respect to a MRfluid-based dashpot, it is envisioned that an ER fluid-based dashpotcould be substituted.

MR fluid changes viscosity dependent upon the magnitude of an appliedmagnetic field—the larger the magnetic field applied, the greater thechange in viscosity of the fluid. ER fluid changes viscosity dependentupon the magnitude of an applied charge—the larger the charge applied,the greater the change in viscosity of the fluid. This change can occurin a few milliseconds. These fluids have been incorporated in adampening mechanism by the inventor of the MR fluid or Rheonetic™ fluidtechnology, Lord Corporation. The present invention incorporates acontrollable rheological fluid, such as the MR fluid, into the automatichead stabilizing system.

According to one aspect of the present invention, an automatic headstabilizing system for protecting the head and neck of a user duringrapid deceleration is provided. The system 300 includes a helmet 310, aconnection structure, at least one MR fluid dashpot 330, and means formonitoring the status of the vehicle and/or driver.

As embodied herein and shown in FIG. 8, helmet 310 and connectionstructure 320 are similar to those previously discussed with respect toFIGS. 1A-1C, 2A-2B, 5A and 5B. The connection structure may comprise ashoulder/chest plate 320 or a portion of the vehicle, such as safetyharness. At least one MR fluid-based dashpot 330 is provided. LordCorporation manufactures a presently preferred MR fluid that is used inthe automatic dashpot of the present invention. Detailed function andstructure of MR fluid-based dashpots may be located on the LordCorporation website www.rheonetic.com.

According to one aspect of the invention, the system 300 includes meansfor monitoring the status of the vehicle and/or driver of the vehicle.The status of the driver of the vehicle may be monitored, for example,by use of an accelerometer on the helmet 310. A baseline accelerationcan be established by driving around the track/course, and wheneveracceleration of the head exceeds the predetermined baseline value, thesystem can initiate the reaction necessary to generate an offsettingreaction force.

The status of the vehicle itself may be monitored, for example, by useof a yaw sensor. Testing has shown that a crash can be anticipated byuse of a yaw sensor in a vehicle. Most vehicles begin to turn sidewaysbefore a crash. By determining a baseline yaw reading, and thencontinuously monitoring the yaw sensor, once the sensor detects a changeof yaw beyond a predetermined baseline value, the present system caninitiate the reaction necessary to generate an offsetting reaction forcebefore the crash occurs. Alternatively, a GPS system may be used tomonitor the status of the vehicle.

By continuously sensing the status of the vehicle and/or driver, it ispossible to continuously change the viscosity of the MR fluid inresponse to either a changing load on the head (accelerometer) orchanging yaw of the vehicle (yaw sensor). Thus, at any given time, thedashpot is adjusted for the real-time status of the vehicle and/ordriver.

In use, the head and body of the wearer are moving at the same velocitywithin the vehicle and little force/load is applied to the wearer'shead. During high acceleration periods, such as when taking corners, theload on the wearer's head and neck increases. The load on the head andneck increases dramatically during a crash situation. The load on thehead and neck may be monitored, for example, by an accelerometer thattransmits the information to a system for applying a magnetic field tothe MR fluid. Alternatively, in a more preferred embodiment, a yawsensor is used to monitor the status of the vehicle, and when the statusexceeds a predetermined baseline value, the system is triggered. Thesystem for applying a magnetic field to the MR fluid adjusts theviscosity of the MR fluid based on the status information. The viscosityof the MR fluid is adjusted such that the dashpots become sufficientlyrigid to generate a reaction force stabilizing the head and preventingany substantial increase or decrease in distance between the head andthe body.

According to another aspect of the invention, a head stabilizing systemfor protecting the head and neck of a user during rapid deceleration maynot include a MR fluid-based dashpot. As embodied herein and shown inFIG. 9, s system 400 includes a helmet 410 and a neck bladder 430.Optionally, the system 400 may be provided with a connection structure420.

The bladder 430 may comprise a rubber inner tube or other hollow tubularinflatable member. Bladder 430 contains MR fluid and a coil (not shown)for applying a magnetic field to the MR fluid. As previously described,the status of the vehicle and/or driver is continuously monitored, forexample by an accelerometer or a yaw sensor. This information issupplied to a control circuit that determines what the viscosity of theMR fluid should be in order to counteract the load on the head. Thecontrol circuit then supplies a current (calculated to provide thedesired viscosity) to the coil, thereby changing the viscosity of the MRfluid.

The bladder 430 may be connected to either or both the helmet 410 andthe chest/shoulder plate 420 and when sufficiently rigid (based upon theviscosity of the MR fluid), the bladder 430 will preventmotion/acceleration of the head and helmet 410 with respect to the bodyof the wearer (and connection structure, if provided). Alternatively,the bladder 430 may be structured such that physical-connections areunnecessary. In such an embodiment, a chest/shoulder plate may not beprovided.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1-60. (canceled)
 61. A passive head stabilizing system for limiting theload acting on a wearer's head and generated by displacement, velocity,or acceleration of the wearer's head with respect to the wearer's body,comprising: a passive resisting member having first and second ends, atleast the first end being configured to be pivotably connected toanother structure; a helmet mount connector configured to pivotablyconnect the passive resisting member to a helmet, the helmet mountconnector being pivotably connected to the first end of the passiveresisting member; and a shoulder/chest plate connector configured toconnect to a shoulder/chest plate worn by the wearer, the shoulder/chestplate connector being connected to the second end of the passiveresisting member.
 62. The system of claim 61, wherein the passiveresisting member is a dashpot.
 63. The system of claim 61, wherein thepassive resisting member is a tether.
 64. The system of claim 61,further comprising a helmet having a mounting device connectable to thehelmet mount connector.
 65. The system of claim 61, further comprising ashoulder/chest plate to be worn by the wearer, the shoulder/chest plateincluding an element configured to connect to the shoulder/chest plateconnector.
 66. The system of claim 65, wherein the shoulder/chest plateis configured to engage at least a portion of safety harness.
 67. Thesystem of claim 61, further comprising a second passive resistingmember, wherein the shoulder/chest plate connector includes means forconnecting to an end of the second passive resisting member.
 68. Thesystem of claim 61, wherein the passive resisting member generates areaction force that substantially opposes a crash impact force to yielda reduced net force on the head.
 69. The system of claim 68, wherein thereaction force generated by the passive resisting member includes avertical component.
 70. The system of claim 68, wherein the reactionforce generated by the passive resisting member includes a horizontalcomponent.
 71. The system of claim 68, wherein the reaction forcegenerated by the passive resisting member includes a vertical componentand a horizontal component.
 72. The system of claim 68, wherein thepassive resisting member is positioned to generate the reaction forcethat substantially opposes the crash impact force to yield the reducednet force on the head at a point below a center of gravity of the head.73. The system of claim 61, wherein the helmet mount connector forconnecting the passive resisting member to the helmet is attached to thehelmet at a point below a center of gravity of the head.
 74. A passivehead stabilizing system for limiting the load acting on a wearer's headand generated by displacement, velocity, or acceleration of the wearer'shead with respect to the wearer's body, comprising: a passive resistingmember having first and second ends, at least the first end beingconfigured to be pivotably connected to another structure; a helmetmount connector configured to pivotably connect the passive resistingmember to a helmet, the helmet mount connector being pivotably connectedto the first end of the passive resisting member; and a connectorconfigured to connect to a component worn by the wearer, the connectorbeing connected to the second end of the passive resisting member. 75.The system of claim 74, wherein the passive resisting member is adashpot.
 76. The system of claim 74, wherein the passive resistingmember is a tether.
 77. The system of claim 74, further comprising ahelmet having a mounting device connectable to the helmet mountconnector.
 78. The system of claim 74, wherein the component worn by thewearer is a shoulder/chest plate, the shoulder/chest plate including anelement configured to connect to the shoulder/chest plate connector. 79.The system of claim 78, wherein the shoulder/chest plate is configuredto engage at least a portion of safety harness.
 80. The system of claim74, wherein the component worn by the wearer is a yoke.
 81. The systemof claim 74, wherein the component worn by the wearer is a harness. 82.The system of claim 74, further comprising a second passive resistingmember, wherein the connector configured to connect to a component wornby the wearer includes means for connecting to an end of the secondpassive resisting member.
 83. The system of claim 74, further comprisinga component worn by the wearer, wherein the component is one of ashoulder/chest plate, a yoke, and a harness.
 84. A passive headstabilizing system for limiting the load acting on a wearer's head andgenerated by displacement, velocity, or acceleration of the wearer'shead with respect to the wearer's body, comprising: a helmet; andpassive means for generating a reaction force that substantially opposesa crash impact force to yield a reduced net force on the head, thepassive means including at least one passive resisting member having abody portion, a first connecting portion, and a second connectingportion, wherein the body portion is positioned between the first andsecond connecting portions and the first connecting portion includes apivoting mechanism and the second connecting portion is configured toconnect to a component worn by the wearer.
 85. The system of claim 84,wherein the at least one passive resisting member includes at least onepassive dashpot.
 86. The system of claim 84, wherein the at least onepassive resisting member includes at least one tether.
 87. The system ofclaim 84, wherein the reaction force generated by the passive meansincludes a vertical component.
 88. The system of claim 84, wherein thereaction force generated by the passive means includes a horizontalcomponent.
 89. The system of claim 84, wherein the reaction forcegenerated by the passive means includes a vertical component and ahorizontal component.
 90. The system of claim 84, wherein the passivemeans is positioned to generate the reaction force that substantiallyopposes the crash impact force to yield the reduced net force on thehead at a point below a center of gravity of the head.
 91. The system ofclaim 84, wherein the at least one passive resisting member is connectedto the helmet at a point below a center of gravity of the head.
 92. Thesystem of claim 84, further comprising a component worn by the user,wherein the component is one of a shoulder/chest plate, a yoke, and aharness.